From 65c2978f43f092d5199a14bb82e4abac2080199c Mon Sep 17 00:00:00 2001
From: Stewart Allen <stewart.allen@gmail.com>
Date: Sun, 21 Sep 2025 17:35:44 -0400
Subject: [PATCH] fixes #421 by removing all non-extended-thru cuts when step
 down is greater than full cut depth of part

---
 src/kiri/mode/cam/op-outline.js | 5 +++++
 src/kiri/mode/cam/op-rough.js   | 9 ++++++++-
 2 files changed, 13 insertions(+), 1 deletion(-)

diff --git a/src/kiri/mode/cam/op-outline.js b/src/kiri/mode/cam/op-outline.js
index 270f4c64..c9b7e275 100644
--- a/src/kiri/mode/cam/op-outline.js
+++ b/src/kiri/mode/cam/op-outline.js
@@ -100,6 +100,11 @@ class OpOutline extends CamOp {
         // extend cut thru (only when z bottom is 0)
         if (workarea.bottom_z < 0) {
             let last = slices[slices.length-1];
+            // when step down > full cut depth, clear slices and
+            // leave only the cut-thru pass(es)
+            if (op.down > workarea.top_stock - workarea.bottom_part) {
+                slices.length = 0;
+            }
             for (let zneg of base_util.lerp(0, -workarea.bottom_cut, op.down)) {
                 if (!last) continue;
                 let add = last.clone(true);
diff --git a/src/kiri/mode/cam/op-rough.js b/src/kiri/mode/cam/op-rough.js
index 341f56d8..beb24827 100644
--- a/src/kiri/mode/cam/op-rough.js
+++ b/src/kiri/mode/cam/op-rough.js
@@ -32,11 +32,12 @@ class OpRough extends CamOp {
         let roughStock = op.all && isIndexed;
         let toolDiam = new Tool(settings, op.tool).fluteDiameter();
         let trueShadow = process.camTrueShadow === true;
+        let cutThruBypass = op.down > workarea.top_stock - workarea.bottom_part;
 
         updateToolDiams(toolDiam);
 
         // clear the stock above the area to be roughed out
-        if (workarea.top_z > workarea.top_part) {
+        if (workarea.top_z > workarea.top_part && !cutThruBypass) {
             let shadow = state.shadow.base.clone();
             let step = toolDiam * op.step;
             let inset = roughStock ?
@@ -258,6 +259,12 @@ class OpRough extends CamOp {
 
         let last = slices[slices.length-1];
 
+        // when step down > full cut depth, clear slices and
+        // leave only the cut-thru pass(es)
+        if (cutThruBypass) {
+            slices.length = 0;
+        }
+        // add cut thru passes
         if (workarea.bottom_z < 0)
         for (let zneg of base_util.lerp(0, -workarea.bottom_cut, op.down)) {
             if (!last) continue;